US scientists have discovered that dark chocolate may be the key to preventing deep vein thrombosis (DVT) in passengers on long haul flights.

Carl Keen, Professor of Nutrition and Internal Medicine at the University of California, told the British Association for the Advancement of Science yesterday: “Eating chocolate rich in flavonoids regularly and as part of a balanced diet, can have positive cardiovascular effects, and may even contribute to a lower risk of blood clots.”

People at risk of DVT, otherwise known as “economy class syndrome”, are often advised to take an aspirin before travelling to prevent the blood clotting. After studying the effects of flavonoids on the blood of 25 volunteers, Prof Keen concluded that eating chocolate appeared to have an “aspirin like effect” on reducing platelet activation and aggregation in blood, both thought to be important factors in blood clotting.

Prof Keen stressed however that travellers should not swap aspirin for flavonoid-rich chocolate yet because they both seem to prevent clotting by different mechanisms. Further research is necessary, he added, before it can be stated that chocolate can definitely prevent DVT.

A spokesman from the British Heart Foundation called any message that chocolate could be good for the heart “reckless” and reiterated that chocolate has a high fat content and people should get all necessary nutrients from eating fruit and vegetables.